Multiple heat electric cooker



Aug. 13, 1929. ZlOLA 1,724,247

MULTIPLE HEAT ELECTRIC COOKER Filed y 1926 3 Sheets-Sheet 1 Aug. 13, lH, Z|Q| A 1,724,247

MULTIPLE HEAT ELECTRIC COOKER Filed May 20, 1926 3 Sheets-Sheet 2 Aug.13, 1929.

H. A. ZlOLA MULTIPLE HEAT ELECTRIC COOKER 1926 3 Sheets-Sheet Filed May20 ill n Patented Aug. 13, 1929.

UNITED STATES 1,124,241 PATENT OFFICE.

HENRY A. ZIOLA, TOLEDO, OHIO, ASSIGNOR TO THE SWARTZBAUGH MANUFACTURING- COMPANY, OF TOLEDO, OHIO, A CORPORATION.

MULTIPIJE HEAT ELECTRIC COOKER.

Application filed Kay 20, 1926. Serial No. 110,496.

The present invention relates in general to electric cookers, and moreparticularly to a device of this character Whichembodies novel featuresof construction, whereby different temperatures may be obtainedseleotively at will.

Among the further objects of the invention are to provide a variableheat electric cooker in which the diflerent heats are obtained by theuse of the same potential the device being adapted to be designed sothat it can be operated on the usual electric light circuit of 110 or120 volts or other voltages.

The invention also contemplates a variable heat electric cooker in whichthe necessity of using a switch to obtain difierent heats is avoided,the desired result being obtained 7 by plugging in at difierentplacesand connecting the main circuit to different terminals.

While one particular embodiment of the invention will be shown anddescribed for illustrative purposes, it will be understood that manymodificationsand changes can be made in the details of constructionwithout departing from the spirit thereof.

For a full understanding of the invention reference is to be had to thefollowing description and accompanying drawings in which,

Figure 1 is a vertical sectional view through a variable heat electriccooker which is constructed in accordance with the invention.

Figure 2 is a transverse sectional view through the same on the line 2-2of Figure 1.

Figure 3 is a side elevation of a portion of the exterior of the cookingWell showing the terminal supports for the resistance wires, portionsbeing broken, away to illustrate more clearly the details ofconstruction. 7

Figure 4 is an enlarged longitudinal sectional view taken on the line 4-1 of Figure 3.

Figure 5 is an enlarged sectional view through the socket, showing thethree con tact pins and the plug which is adapted. to be selectivelyapplied thereto in different positions.

Figure 6 is a wiring diagram.

Figure 7 is a vertical sectional view of a modification of theinvention.

Figure 8 is a horizontal sectional view through the modified form ofcooker of Figure 7.

Corresponding and like parts are referred to in the followingdescription and indicated on all of the views of the drawings by likereference characters.

The outer shell or casing of the cooker can be constructed in anydesired manner, although for illustrative purposes it is shown ascomprising a main cylindrical section 1, which has a bottom section 2connected to the lower edge thereof and a top section 3 connected to theupper edge thereof. The top section is in the form of string and sup-'ports a cooking well 4 which has itsupper end secured thereto. Thecooking well is spaced from the outer shell and the space is perferablyfilled with some heat insulating material such as mineral wool 5. Thefood A to be cooked is placed in the cooking well 4:

and the cooker closed by means of a cover 6 which is applied to theupper end of the cooking well. The cover may have the usual handle 7applied thereto, and where the device is portable a conventional bail 8may be connected to the outer casing.

A sheet of asbestos or similar material is wound around the exterior ofthe cooking well 4 to provide an insulating cover of suitable thickness.As shown on the drawings there are two thicknesses of asbestos 9extending around the periphery of the well.

Two resistance wires 10 and 11, respectively, are wound around theasbestos 9 in helical form, each turn of one of thewires being locatedbetween two turns of the other wire. The two resistance wires are thusseparated from each other andwound over a large portion of the area ofthe cooking well so that the heat from the resistance wires will beevenly distributed. In order to bring about a more even distribution ofthe heat the convolutions of the resistance wires at the middle of thecooking well are spaced a considerable distance apart, as indicated onthe drawings, because there is less .loss of heat by radiation at themiddle of the cooking well than atthe end portions thereof. After theresistance wires have been wound around the insulating layer 9, they arecovered with a plastic cement 12 of a character which is well known inthe art. The resistance wire 10 is of greater diameter than the resstance wire 11, so that it will ofier less resistance to the passage ofelectric current than the smaller diameter wire 11 and become heated toa higher degree of .heat than the latter wire, when the same voltage isapplied.

-A metallic strip 13 is arranged under the q insulating covering 9 andextends longitudinally of thecooking'well. The upper and lower ends ofthe metallic strip 13 are eni lava insulating block wire is secured tothe plate 18 by a second spective resistance wires are threaded.

screw 21. The lower lava insulating block .16 is formed with a pair oftransverse openings through which the lower ends of the re- The outershell is provided at the bottom thereof with a socket 23; A la ainsulating resistance wire 10 is connected to.the inter- -mediateterminal stem 25 and the lower end block 24 is arranged at the inn r endof the socket and three terminal stems 25 project from the saidlavainsulating block 24 into the socket. As is indicated more clearly bythe wiring diagram, the lower end of the resistance wire 11 is connectedto the end terminal stem 25, while the lower end of the of the terminalwire 20 is connected to the other end terminal stem 25. The plug 26, bymeans of which connection is made with the electric circuit, is of aconventional construction, being adapted to engage two of the terminalstems 25. It will be understood that it can be applied to theintermediate terminal stem 25 in combination with either of the endterminalistems. When the plug is applied in one position, the electriccurrentis caused to pass through the resistance wire 10 without passingthrough the resistance wire 11, and the heavy wire is then heated toproduce a high temperature heat. When the connecting plug 26 is appliedto the other pair of, terminal stems, it will be obvious that theelectric current flows through both of the resistance wires in series,so that a low heat is obtained. The same potential is used, how- ]ever,for obtaining the high heat or the low heat. It might, of course, bearranged so" that the current would pass through the fine wire alone toobtain a low heat and through the larger gauge wire alone. to obtain thehigh heat, although it has been found that more economical results areobtainable where the current is permitted to pass through both of theresistance wires in series when the low heat is desired.

cookingwellu Where the usual 110-120 volt electric lighting circuit isto be used it has been found that good resultscan be obtained by using asufiicient length of #21 gauge wire to give a resistance of 31 ohms, anda suflicient length of #26 wire to have the resistance'of'98 ohms. About38 feet of each length of wire will be required, and when both units arein series the combined resistance will be 129. ohms. When the high heatis on approximately 400 watts at 120 volts will be used, while when thelow heat is on approximately 100 watts will be used. The

high heat can be employed for starting water to boil orinitially heatingthe contents of the cooking well, while after the water has reached theboiling .point or the contents of the cooking shell have been thoroughlyheated, the low heat will be sufficient to continue I the cooking.operatlon without danger of burning the contents of the cooker.

The reason both the No. 21 and 26 resistance wires are.used in seriesfor a low heat is because the total of the 129 ohms is thus obtained,and the No. 21 resistance wire is made to function for both the low heatand high heat connections. An additional 81 ohms is obtained by usingthe. N o.

21 gauge in series with No. 26 gauge (of 98 ohms) making atotal of 129ohms, although as stated previously the No. 26 gauge resistance wirecould be used alone for the low heat connection, although there iseconomy in using both of the resistance wires in series for the low heatconnection.

A modification is indicated by Figure 7, the mineral wool or otherpacking interposed between the cement 12 and the outer wall 1 beingomitted. An open space is left between the outer walland the cement, ithaving been found that under many conditions the open-space will providea proper heat insulation for the inner receptacle.

It is obvious, of course, that instead of winding the two resistancewires helically around the cooking well with the convolutions of oneresistance wire arranged between the convolutions of the otherresistance wire, the two resistance wires may be wound in superposedlayers with insulating material between the same, or the two resistancewires may be wound around different portions of the cooking well.

Moreover in this particular construction the lava or insulating blocks15 are attached to a metal member or cylinder which surrounds thecooking well 4, instead of being secured by a metallic strip 13. Inother words, there is provided the reinforcing cylinder 30 whichperforms two functions, namely provides first a reinforcing, packing forthe cooking well and secondly it forms an attaching member equivalent tothe metal strip or plate 13 previously described.

\ well, a layer of insulatin or packing, as above set forth, I havefound that under certain conditions the non-use ing well, a layer ofinsulating material ex-' tending around the same, a strip under theinsulating material, a resistance wire wound around the insulatinglayer, and blocks of insulating material connected to the strip, saidblocks of insulating material serving to engage the ends of theresistance wire.

2. An electric cooker including a cooking well, a layer of insulatingmaterial upon the well, a strip extending under the insulating layer, aplurality of resistance wires wound upon the insulating layer,insulating blocks connected to the before mentioned strip and supportingthe terminals of the resistance wires, and means for selectivelyconnecting the main current to the resistance wires to obtain differentdegrees.

of heat.

3. An electric cooker including a cooking material extending around thewell, a strip arranged under I the insulating layer, a plurality ofresistance wires wound upon the insulating layer, insulating blocks atthe end of the strip, fastening members extending through the insulatinglayers and securing the blocks to the strip, the ends of the resistancewires being supported by the blocks, and means for selectivelyconnecting the main current to the resistance wires in order to obtaindifferent degrees of heat.

4. An electric cooker including a cooking well, a layer of insulatingmaterial extending around the well, a strip arranged under theinsulating material, a pair of resistance wires wound helically aroundthe insulating layers with the convolutions of one resistance wirereceived between the convolutions of the other resistance wire,insulating blocks supported by the strip, .a

terminal member on one of the insulating blocks to which the tworesistance wires are connected, the other insulating block supportingthe ends of the resistance wires independently, and means forselectively causing the main current to pass through one of theresistance wires or through the two resistance wires in series to obtaindifferent degrees of heat.

5. An electric cooker including a cooking well, a layer of insulatingmaterial extending around the cooking well, a strip extending under theinsulating layer, a pair of resistance wires wound helically on theinsulating layer with the convolutions of one resistance wire receivedbetween the convolutions of the other resistance wire, insulating blockscarried by the ends of the strips, a terminal plate mounted upon one ofthe insulating blocks and having the ends of both insulating wiresconnected thereto, the other insulating block being formed with openingsthrough which the resistance wires are carried, and means forselectively connecting the main electric current to the resistance wiresin order to obtain different degrees of heat.

6. An electric cooker comprising a cooking well, a metallic memberapplied to said well, a layer of insulating material surrounding thewell and said metallic member, resistance wire wound about theinsulating layer, insulating blocks attached to the metallic memberaforesaid, and terminal means connected with said insulating blocks.

7. An electric cooker comprising a cooking well, a metallic memberapplied to said well, a layer of insulating material surrounding thewell and said metallic member, resistance wire wound about theinsulating layer, insulating blocks attached to the metallic memberaforesaid, and terminal means connected with said insulating blocks, theends of the resistance wire being connected with the insulating blocksso as to hold the resistance wire in place upon the insulating layer.

In testimony whereof I afiix my signature.

